<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>

		<script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
	</head>
	<body>

		<div id="app">
			{{num}}<br />
			<input type="text" v-model="num" />
			<br />
			{{message}}
			<br />
			{{result}}

		</div>

		<script>
			var app = Vue.createApp({
				data() {
					return {
						"message": "hello Vue!",
						"num": 10,
						"result": 0
					}
				},
				methods: {
					sleep(n) {
						var now = new Date();
						var exitTime = now.getTime() + n;
						while (true) {
							now = new Date();
							if (now.getTime() > exitTime) {
								return;
							}
						}
					}
				},
				watch: {
					num(newVal, oldVal) {
						console.log("旧的值" + oldVal)
						console.log("新的值" + newVal)
						this.message = "监听到num数据改变了，旧的值" + oldVal + "新的值" + newVal
						this.sleep(2000)
						this.result = Math.sqrt(parseInt(newVal))
						console.log(this.result);
					     
						var  worker = new worker("longtask")
						
						
					}
				}
			});

			var vm = app.mount("#app");
		</script>
	</body>
</html>
